Open-mold casting

In open-mold casting, the shape of the desired object is carved as a "negative" depression or hollow into a suitable bulk of material that withstands the temperature required for the process wood is often used for cold casting molds stone, sand, and dry mud, for hot casting. The fluid casting material is then poured into the carved depression, where it is left to set and from which, when solid, it is finally removed. 

Along with the simple open-mold casting method, there are several other methods of casting polyurethanes. They include ... 

Hybri-Chem. [Hybti-Chem] Polyesto/ polyurethane hybrid system for open mold casting, lamination, spray appUc., resin transfer molding, tooling. 

Chem. Descrip. Proprietary resin in aliphatic hydrocarbon solv. blend Uses External mold release for polyester, vinyl ester, and epoxies for open molding, cast polymers, cultured marble, and parts requiring exc. finishes... 

Polyester can be used to fabricate a variety of products by many techniques such as open-mold casting, hand layup, spray-up, vacuum-bag molding, matched metal die molding, filament winding, pultrusion, encapsulation, centrifugal casting, and injection molding. 

Although more and more zinc sheet and strip are produced in continuous mills, some is stiU produced by rolling slabs cast in open or closed book-type molds made of cast iron (124—127). The casting temperatures are between 440 and 510°C, mold temperatures between 80 and 120°C. The contact surfaces of the mold must be smooth and clean to allow unrestricted shrinkage of the cast slab. Mold lubricant is not necessary, but if used should be held to a minimum. Slabs cast in open molds must be skimmed immediately to remove surface oxide. Rolling slabs are cast 1.87—10 cm thick. 

Zinc rolling slabs have been cast successfully by semicontinuous direct-chill casting methods. This is the preferred method for superplastic zinc alloys which, because of their large freezing range, display unacceptable surface shrinkage when cast in open molds. 

Some TPs and TSs begin as liquids that can be cast and polymerized into solids. In the process various ornamental or utilitarian objects can be embedded in the plastic. By definition, casting applies to the formation of an object by pouring a fluid plastic solution into an open mold where it completes its solidification. Casting can also lead to the... 

When the mixture of monomers is cast in an open mold, the air bubbles formed at the jet nozzle in the mold usually have enough time to leave the material due to the low viscosity of the reactive liquid. When more viscous oligomers and prepolymers are used, particularly in the case of low-lifetime reactive mixtures, it may be necessary to use some simple procedures, for example, filling through a pipe immersed into the mold, to prevent the formation of air bubbles in the product. 

Sheets of Class SC (caulking compounds) elastomers, 0.16 cm thick, were prepared by casting the caulks in open molds, 15 cm X 2.5 cm. The bottom of the mold was covered with a thin sheet of Mylar, which had been coated with a silicone and then a fluoro-... 

Uses Initiator, crosslinking agent, detackifier for low temp, or photocured free radical polymerizations, peroxide-cured adhesives, cast vinyl or acrylic sheet, high-solids peroxide-cured coatings, open-mold peroxide-cured composites, UV-cured coatings (esp. pigmented)... 

Castings are usually used for decorative articles, and bowling balls. The resole resin containing diluents, iilleis, and pigments are cast into open molds and maintained there during curing [1]. 

Casting. Umeinforced polyester is poured into an open mold, typically silicone rubber, and cured to produce bathroom sinks, counters, tubs, showers, and toilets giftware, art objects, and cultured marble and onyx (Table 3.21). Appearance is controlled by choice of fillers. 

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